The present invention relates generally to agricultural implements and more specifically to a combination tillage and seeding implement including furrow opener and press wheel gangs mounted in trailing relationship to the rear beam of a field cultivator or similar type tillage implement for one-pass planting of small grains.
In many farming areas, a till and drill system is employed to both work the soil and plant small grains such as wheat, oats or rye in a single operation. This system reduces the time and fuel required to plant, reduces soil compaction, and conserves moisture since the furrow is formed and compacted immediately after the soil is worked. Where such a combined operation is advantageous, terraces or rolling terrain are common so that the furrow openers must have a large range of vertical travel with reasonable down pressure in the extreme positions for uniform seeding. If the down pressure on the furrow openers is not compensated for changes in toolbar or frame elevation or rotation caused by rolling or terraced ground, changes in seeding depth will result in uneven stands. Presently available seeding systems include those which utilize relatively heavy furrow opener parts coupled with detachable torsion springs for adjustable down force. The mounting toolbar is hydraulically rotated to adjust force when the implement crosses terraces or the like. Such systems are relatively massive and expensive, and require hydraulic assist systems. As the number of moving parts increases, system reliability typically decreases. Usually the systems utilize many components which vary from those utilized with other types of drills thereby increasing production costs and the amount of inventory carried by the manufacturer and dealers.
In many till and drill systems, adjustment of the furrow openers for either staggered or in-line operation is not easily accomplished. In fine soil where few rocks or clods are present, the drilling speed can be increased by maintaining the openers in alignment, while staggering the openers reduces clogging problems in soil where rocks and clods are numerous. However, providing such an adjustment has often been relatively expensive, and converting between staggered and in-line arrangements can be a difficult and time-consuming job.
Another problem encountered with combination tillage and drilling arrangements has been providing a compact structure with adequate flexibility. Systems utilizing tandem hitching arrangements for towing a drill behind a tillage implement are usually cumbersome and difficult to connect up and maneuver. Changing between field-working and transporting modes often is time-consuming and may require more than one person. Press wheels mounted at the rear of an implement behind the turning center will be subjected to severe side forces as the implement is turned either way from the forward direction. Mounting press wheels far behind furrow openers on a single frame causes a tracking problem when rows are planted other than in a straight line.
It is therefore an object of the present invention to provide an improved planting system. It is a further object to provide such a system which achieves a more uniform furrow opener penetration even in terraced or rolling fields without need for relatively heavy opener parts or hydraulic assist systems.
It is another object to provide an improved drill system with furrow openers that have a large vertical travel range with a generally uniform down pressure over substantially the entire range.
It is a further object to provide a toolbar-mounted furrow opener arrangement for a drill which compensates for changes in toolbar elevation or rotation to maintain an even down pressure on the opener. It is still another object to provide such an opener arrangement which advantageously utilizes the vertical rocking of press wheel standards to compensate for elevational or rotational changes in the toolbar and achieve uniform depth of penetration of the furrow opener.
It is yet another object of the invention to provide an improved tillage and drilling implement for tilling the ground and uniformly planting small grains in a single operation, even on terraced or rolling ground. It is another object to provide such an implement which is relatively low in cost and yet is reliable and versatile. It is a further object to provide such an implement which is mounted on a single main frame.
It is another object to provide an improved furrow opener and press wheel gang assembly for mounting on the rear of a tillage implement. It is still another object to provide such an assembly having reduced side forces during turns as well as a large range of vertical travel with independent relative vertical movement of individual press wheels in the assembly.
In accordance with the above objects, a plurality of furrow opener and press wheel gang assemblies are mounted on the rear beam of a frame of a field cultivator or similar type of tillage implement. Preferably two spring shank assemblies are connected to the rear beam and include fore-and-aft extending standards pivotally connected thereto and extending rearwardly to a transverse beam which connects the rear portions of the standards. A plurality of press wheels are individually connected to the beam at transversely spaced locations by pivots and structure which includes a resilient bushing to permit independent castering and limited vertical movement of the individual press wheels relative to the beam. Rearwardly of the pivotal connection of the standards to the spring shank assemblies, a hat-shaped channel member is bolted across the standards and pivotally supports a plurality of drawbar members attached to furrow openers directly ahead of the corresponding press wheels. A spring is tensioned between each furrow opener and an adjustable arm member pivotally connected to the rear beam of the frame to adjustably bias the furrow opener downwardly into the ground. The moment arm through which the spring acts to bias the furrow opener downwardly decreases as spring tension increases as a result of the standards pivoting upwardly. The upward pivoting moves the pivot center of the furrow opener assemblies closer to the line of action of the spring. Therefore, as the press wheels are biased upwardly and move the standards upwardly about their pivotal connection with the frame, the spring force increases on the furrow opener as it will be moving upwardly, but simultaneously the moment arm decreases to provide a fairly uniform down pressure on each furrow opener. A large range of vertical travel is therefore provided with a uniform down pressure over the range. The castering press wheels permit the furrow opener and press wheel gang assembly to be mounted well to the rear of the turning center of the implement without excessive side forces being exerted on the assembly. Furrow opener down pressure for each of the gang assemblies can be adjusted in a single operation. The drawbar members for each of the furrow openers can be connected either to the front or rear portion of the hat-shaped channel so that staggered or in-line furrow operation may be easily achieved with a minimum number of new components.
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the description which follows and from the drawings.